1g n/t swap

[titengo]

A friend of mine bought a 91 gsx but the previous owner swapped the engine to a J-spec n/t and never got it running. We got it running but it won't idle like it's supposed to (appears to be running on 3 cyl). The thing is we are not sure if it's the mas, if the turbo and n/t mas are the same, if the wiring is the same. we are kinda lost here any help/suggestions would be aprreciated.

 

[freshlane]

need to remove the injector resistor pack. Clip the wires from the pack. The wires going to the harness need to be connected all together, it just eliminates the resistor. It is the opposite of the turbo converison. Also you need to swap a few wires for the maf. (below is a clip from the conversion chart i created - http://dsmtuners.com/forums/showthread.php?t=242183). If that doesn't work I would suggest you look at the turbo conversion threads and go backwards

1G TURBO MAF

1 - Idle position switch
2 - Air flow sensor (signal)
3 - MPI control relay
4 - 5V power supply
5 - None
6 - Ground
7 - Barometric pressure sensor
8 - Intake air temperature

1G N/T MAF

1 - Air flow sensor (signal)
2 - MPI control relay
3 – 5V power supply
4 – Ground
5 – Barometric pressure
6 - Intake air temperature

 

[titengo]

So I just cut the wires from the resistor and put the together, ok. Another thing is that he bought a mas that it is supposed to be for the n/t (it's different than mine) the plug is the same but the sensor is a lil bit different does that matter? Are the turbo and n/t sensor the same? Should i put my sensor to try it?

Also it has the turbo injectors, can it be running rich?

 

[freshlane]

Yep just cut the wires and put them together. The injectors use a grounding circuit the 12v is constant and the ECU activates the grounds for them. Yes it does matter with the MAS. If you look at the chart the pins are different. Put the NT MAS on. You will also need to swap the injectors because the 550s are low impendance injectors and will not work correctly without the resistor (which you are going to remove), I believe it will actually mess them up. Go get some 250s from your local junkyard and plugs those in. YOU MUST SWAP INJECTORS. YOU MUST TAKE OUT THE RESISTOR PACK and YOU MUST CHANGE THE MAS. After that it should start right up.

 

[titengo]

thanks man will do that later on right now it's party time

 

[freshlane]

koolio. have fun